I've heard most of the speakers mentioned here, but not the Blumenhofer or OHA speakers. I like a lot of these speakers, but, I prefer the custom builds I've heard, particularly because they are specifically tuned to the buyer's taste and room acoustics. The builder in my area, Deja Vu Audio, utilizes a mix of vintage and modern drivers and parts, but the key ingredients are rare, vintage midrange drivers and horns.
Most of the systems mentioned above are quite good, so any specific ones I particularly like are those that happen to fit my personal preference so they are not necessarily better than the others. For example, I like the JBL Everest even if the overall tonal balance is not quite warm enough for my taste. I have heard many vintage JBL horn systems and that company has remained pretty consistent in its overall sound. Likewise, I like the Classic Audio systems--the JBL Hartsfield reproduction and the field coil speakers, but, they are too bright for me to truly love them. Avantgarde Duos and Trios are very nice too, but, for me the bass does not match the rest of the sound and seems a bit "slow" and lumpy (still a fantastic sounding brand). Its been a while since I heard the Odeons, but, I liked them too. Voltis are very good for the money, and have very well built cabinets, but, the ones that look like Classic Klipsch speakers sound like improved Klipsch and don't quite have the magic of the very best horn systems from the past. The smaller Volti (is that the Razz?) is a nice and lively system, but, the bass does not quite match the rest of the sound (still a very good speaker at a very reasonable price).
Someone mentioned the Charney Audio speakers. I don't know if they qualify as horn systems, although the cabinet is often called a quarter wave back loaded horn (I think of horns as having compression drivers for the midrange/tweeter). They are, to me, fantastic sounding, particularly for the money, and they most certainly do sound like horn systems. They don't deliver truly deep bass with impact, but, that is not a big personal priority and they do so much of everything else so well. The same goes with Songer Audio's field coil speakers--not horns, but horn-like in sound (very fast, dynamic and lively sounding, particularly at low volume levels).
